A Saudi father gave his ex-wife the shock of her life when he informed her he was taking their 10 and 11 year-old-sons to join Islamist militants in Syria.

He told her to count them as “birds in heaven”, Saudi-owned media reported.

The pan-Arab al-Hayat newspaper said on Tuesday that the unsuspecting mother had been told that her sons, Abdullah and Ahmed, were going on holiday with their father, identified as Nasser al-Shayeq, in a neighboring Gulf Arab country when she saw an Instagram photo of them in Turkey.

Al-Hayat said she telephoned her son to ask about the photo.

But she got a message from her ex-husband, a former Saudi civil servant, to say that he was taking the boys to Syria to join Islamic State, one of the most militant groups fighting to topple President Bashar al-Assad.

“Count your children as birds in heaven,” Mr Shayeq said in his message, according to al-Hayat, suggesting that they may be killed and become young “martyrs”.

Fellow Islamic State militants later posted a photo of the father and his two sons crouching in front of Islamic State’s black flag, with each boy brandishing an AK-47 rifle in one hand.

The father was smiling as one of the boys also held a grenade in his other hand.

Many Saudis have joined foreign Islamist militant groups.

But another Saudi newspaper, al-Riyadh, said the involvement of children in this case had jolted the Saudi government into action, setting up a hotline with the Turkish government to try to bring the two boys home.